Abstract
We first discuss opportunities and challenges facing the introduction of spatial channel networks toward
the forthcoming space division multiplexing (SDM) era. Then, we present spatial-channel cross-connect
architectures and show that hierarchical spatial bypassing and spectral grooming are beneficial in the
SDM era in terms of total node-cost reduction and optical reach extension. Finally, we show an ultra-
wideband, compact, low insertion loss and low-polarization-dependent-loss five-core 1 × 8 core selective
switch prototype employing a two-dimensionally arranged MEMS array.
